1. Field of the Invention
The present invention relates to communications systems and, in particular, to an improved system for providing routing in a gatekeeper in an IP telephone network.
2. Description of the Related Art
The Internet Protocol (IP) is one of the most popular packet communication and networking protocols being used today. It finds use both on the Internet and in wide area networks (WANs) and local area networks (LANs), such as asynchronous transfer mode (ATM) and Ethernet networks. The promise of inexpensive voice telephony using the Internet has led to extensive interest in “Voice over IP” (VoIP) and “Telephony over LAN” (ToL) applications. In particular, several IP telephony protocols have been developed, including the H.323 Recommendation suite of protocols promulgated by the International Telecommunications Union (ITU). Details concerning the H.323 Recommendation may be obtained from the International Telecommunications Union; the H.323 Recommendation is hereby incorporated by reference in its entirety as if fully set forth herein.
A gatekeeper is an H.323 entity that essentially provides routing and various control functionality. More particularly, the gatekeeper may be programmed with one or more numbers associated with system users, and will attempt to direct calls to the appropriate number. For example, a user may be provided with a work number (coupled to the LAN); a home number; a mobile number; and a voice mail number. When a call is received by the gatekeeper, the gatekeeper follows a set of routing rules to reach the called party.
In certain systems, gatekeeper tries one number after another (e.g., three or four rings in each case) until it is able to reach the user or all numbers associated with the user have been tried at least once. Because the system has no intelligence, it can take a long time before the user is reached.
In some systems, a user can set “time rules,” wherein the call is routed to a user at a particular number at a particular time. However, such systems are unable to adapt to changes in the user's schedule unless the user manually changes the rules each time. A slight change in schedule could result in a long wait for anyone trying to contact the user.